Mr William Stephen Penrose1, Dr Alexander Piper2, Dr John Paul Cunningham2,3, Dr Coral Warr1

1Department of Biochemistry and Chemistry, La Trobe University, Bundoora 3083, Australia, 2Agriculture Victoria Research, AgriBio Centre, Bundoora 3083, Australia, 3School of Applied Systems Biology, La Trobe University, Bundoora 3083, Australia

Biography:

Stephen Penrose is a PhD candidate at La Trobe University, focussing on the olfactory system of the Queensland Fruit Fly. He holds a Bachelor of Biological Sciences and Master of Biotechnology and Bioinformatics from La Trobe University, with his thesis ‘Identifying and characterizing expression patterns of the Bactrocera tryoni odorant receptor family’. After a short stint working as a Research Assistant characterising the olfactory receptors of the Australian Sheep Blowfly, he has returned to continue his work on the Qfly, in collaboration with Agriculture Victoria Research, functionally characterising the odorant receptors identified in his Master’s thesis. While Stephen’s interest in genetics began with wanting to explore the potential of gene editing, he has found a rewarding career in entomology, merging his studies of genetics with his personal hobby of insect keeping.

Abstract:

Bactrocera tryoni, the Queensland Fruit Fly, is one of Australia’s most economically important pests, costing the horticulture industry an estimated $300 million annually. Following the withdrawal of conventional insecticides used to control this pest, there is urgent industry demand for novel control methods that are compatible with Integrated Pest Management (IPM). A promising avenue involves attract and kill approaches using semiochemical lures, however, despite extensive chemical ecology research there is currently no effective lure on the market for the fruit damaging female Qfly. Here we take a different approach, focusing instead on the chemosensory machinery responsible for the detection of these volatiles by the insect, specifically the olfactory receptors (ORs). In this study we identified ~90 putative OR genes in the Qfly genome and characterised their sex-specific expression patterns across antennal and palp tissues. Comparative analysis across Tephritid pests with similar ecological niches revealed an expansion of OR genes known to be involved in the detections of esters, volatiles produced by fruits. Moving forward, key receptors will be functionally characterised through transgenic expression in the ‘empty neuron’ system of D. melanogaster, a well-established model for determining the ligands of odorant receptors. Through an improved understanding of the molecular basis of Qfly olfaction, we can improve OR response prediction models, expanding the range of potential lure components and overcoming the limitations of traditional chemical ecology approaches.